/**
 * Licensed to the Apache Software Foundation (ASF) under one or more
 * contributor license agreements.  See the NOTICE file distributed with
 * this work for additional information regarding copyright ownership.
 * The ASF licenses this file to You under the Apache License, Version 2.0
 * (the "License"); you may not use this file except in compliance with
 * the License.  You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package org.apache.lucene.spatial.geometry;

/**
 * Abstraction of the idea of a calculator of distance between 2 points.  This is useful since while the world is curved,
 * its not always necessary to calcuate the distance between 2 points as if they are on a curve.
 */
public interface GeoDistanceCalculator {

  /**
   * Calculates the distance between the point defined by the source latitude/longitude and the point defined by the
   * target latitude/longitude
   *
   * @param sourceLongitude Longitude of the point the distance is being calculated from
   * @param sourceLatitude Latitude of the point the distance is being calculated from
   * @param targetLongitude Longitude of the point the distance is being calculated to
   * @param targetLatitude Latitude of the point the distance is being calculated to
   * @param units Unit of distance the result should be returned in
   * @return Distance between the 2 points in the units of distance requested
   */
  double calculate(double sourceLatitude, double sourceLongitude, double targetLatitude, double targetLongitude, DistanceUnits units);
}
